Turbocharged GP motorcycles

In 1985, Honda developed a water-cooled turbocharged 250cc V-twin engine that developed 150bhp at 20,000rpm.
Each cylinder had its own turbocharger, with a carburettor located outside of the turbocharger.

Honda believed that the FIM were going to ratify new rules which allowed 250cc turbocharged bikes to compete with normally-aspirated 500cc bikes. However, the FIM never ratified the "2:1 ratio" rule, and so the bike was never completed and raced.

I think it is, the FIM never intended a reversal and getting back to blowers again, even with a capacity handicap. In these days without traction contol, a turbocharged bike with the expectable peaky power curve would have been too much even for Freddie Spencer I assume.

Do sidecars count? I vaguely remember magazin reports on Markus Bösiger trying a turbo engine. But I have no idea if it was ever raced in a GP or only taken to the track in practise. This Swiss website shows a picture (though not a very telling one) of the bike resting in Bösigers collection: